Number of regions in certain maps.

Terms

a(0) =1a(1) =2a(2) =3a(3) =4a(4) =6a(5) =8a(6) =11a(7) =15a(8) =21a(9) =28a(10) =39a(11) =53a(12) =99a(13) =137a(14) =186